Inasmuch as most passenger vehicles and the like include rear overhang portions, which project considerably rearward of the rear wheels of the vehicle, and trailer hitches are constructed in a manner such that the forward tongue portion of a trailer towed behind such vehicles are actually coupled to the vehicles at a point spaced slightly rearward of the rear bumpers of the vehicles, any slight left and right lateral shifting of the forward end of the towing vehicle results in right and left lateral shifting, respectively, of the forward end of the trailer.
This operational feature of the combination of a passenger vehicle and a trailer being towed there behind can be very dangerous, especially when the vehicles are moving at highway speed, such that the vehicles are having momentums such that a sudden lateral changing of direction of the towing vehicle can cause a serious swaying problem of the trailer.
Because the towing vehicle rearward end displaces to the side that is opposite to its forward end, it is especially dangerous when vehicles are in a down hill situation such that the weight of the trailer adds to the momentum of the trailer and the trailer has the tendency to push the towing vehicle rearward end off the moving course.
The towed vehicle-swaying problem is also pronounced when the towed vehicle has a large side elevation area upon which crosswind gusts and slip stream blasts may act on the towed vehicle for creating a sudden unstable condition.
Accordingly, a need exists for a hitch connection between a vehicle and a trailer that eliminates the swaying tendencies of the vehicle and trailer combination as a result of slight lateral shifting of the forward end of the towing vehicle.
Various solutions to the problem of trailer swaying have been proposed with anti-sway trailer hitches that include at least some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 2,201,660, 2,913,256, 3,254,905, 3,785,680, 3,787,077 and 3,825,282.
The most closely related improvement in anti-sway trailer hitch assemblies was disclosed in U.S. Pat. No. 6,485,046, by the present inventor. But, the '046 patent hitch assembly has a limitation for limiting the towing vehicle turning angle, such that, at a larger turning angle, the control rod that connects the hitch beam to the control beam will move closer to and interfere with the intermediate bar on the hitch assembly, thus limiting the towing vehicle turning angles.